Plasma membrane (PM) from dictyostelium discoideum (Dd) was isolated on positively-charged beads. The basic procedure was to adhere the negative-charged cells to the positively-charged beads and after excess cells were removed, the attached cells were disrupted by sonication and the debris washed away. Since the part of the cell in contact with the bead was so strongly adsorbed, the disruption procedure left the beads coated by plasma membrane. The above procedure exposed the cytoplasmic face of the PM to the bathing medium while the outer surface adjoined the beads. The PM with its associated cytoplasmic components was resolved by gradient polyacrylamide gel electrophoresis. The purification of the PM was improved by neutralizing bare polylysine on the bead surface by addition of an anionic polymer. The bare regions occur between attached cells which are so close together that another cell cannot fit between them. The bare regions can become contaminated by cellular debris created during the stage of the isolation scheme when the attached cells are purposefully disrupted. The purification was increased from 15- to 30-fold. Contaminants by non-plasma membrane proteins were reduced as indicated by marker enzymes.